Estimation of Yield Losses of Potato Late Blight PDF

 Submitted by PRAKRITI DEBNATH Reg. No. 005-PG-HORT-21-22 Course name: Agro Meteorological Aspects of Crop Protection Course No. AGM- 602 (2+1) Department of FLORICULTURE AND LANDSCAPING Course Instructor - : Prof. Manoj Kumar Nand The area under the disease progress cur...

 Submitted by PRAKRITI DEBNATH Reg. No. 005-PG-HORT-21-22 Course name: Agro Meteorological Aspects of Crop Protection Course No. AGM- 602 (2+1) Department of FLORICULTURE AND LANDSCAPING Course Instructor - : Prof. Manoj Kumar Nand The area under the disease progress curve (AUDPC) is a useful quantitative summary of disease intensity over time, for comparison across years, locations, or management tactics. The most commonly used method for estimating the AUDPC, the trapezoidal method, is to discretize the time variable (hours, days, weeks, months, or years) and calculate the average disease intensity between each pair of adjacent time points (Madden et al. 2007). The sample time points can be considered in a sequence {ti}, where the time interval between two time points may be consistent or may vary, and associated measures of the disease level is {yi}. y(0) = y0 is the initial infection or the disease level at t = 0 (i.e., the first disease severity observation ). A(tk), the AUDPC at t = tk, is the total accumulated disease until t = tk, given by :  From the above chart it can be easily interpretable that of Treatment-5 is most affected and Treatment3 is least affected by potato late blight disease. AUDPC calculation for Treatment-1: For the computation of AUDPC the areas under the curve have been transformed to a triangle and trapezium and then the areas of each part have been added.  **AUDPC calculation for Treatment-2:**   **Yield loss can be computed as --** **Yield from Disease free field - Yield from infected crop ×100** **Yield from Disease free field** If the disease-free crop is not there the potential yield may be considered Here, the Yield from Disease free field i. e. control plot is 28 tons ha-1 Comparison of Yield and AUDPC for the whole data set: The correlation between yield loss and AUDPC can be calculated. The relation may not be found significant. In such cases, it might so happen that the infection at a certain critical growth stage might be more influential than the overall infection throughout the crop period. In such cases, disease infection at critical growth stages may be tested for correlation.  **Result and Discussion:** From the above dataset it can be concluded that Treatment-3 is least affected as it gives the highest yield of 23 tons ha-1 and its yield loss is 17.85% and AUDPC in % days (i.e. the accumulation of daily percentage infection value) is 1700. Treatment-5 is severely affected as it gives the lowest yield of 12.5 tons ha-1 and its yield loss is 55.35% and AUDPC in % days is 4145.